The human rights group Amnesty International has demanded China release all those it has jailed for expressing views or sharing information online.

It says at least 33 people have been detained for internet subversion and two prisoners had subsequently died after apparent torture or ill-treatment.

Anyone surfing the internet could potentially be at risk of arbitrary detention and imprisonment

Amnesty International

In a report addressing "State control of the internet in China", the advocacy group said Beijing was creating a new category of "prisoner of conscience" by its actions.

A government spokesman said he was not aware of the new report, but said Amnesty had published critical claims before "with no basis whatsoever".

China now has more internet users than any country in the world apart from the US.

The China Internet Network Information Centre said the number of web users soared by 12 million people in the first six months of this year to reach 45.8 million users.

The study from London-based Amnesty International said even merely curious users of the internet could get ensnared in China's regulations.

Amnesty said: "Internet users are increasingly caught up in a tight web of rules restricting their fundamental human rights.

"Anyone surfing the internet could potentially be at risk of arbitrary detention and imprisonment."

Policeman imprisoned

Among the 33 people detained or jailed for offences related to their internet use were political activists and writers as well as members of unofficial organisations such as the Falun Gong spiritual movement.

Two members of Falun Gong detained on internet charges later died

The two people who died in custody, the group alleged, were members of Falun Gong, which has been banned by Beijing as an "evil cult".

Amnesty said a former police officer, Li Dawei, was the subject of one of the longest sentences.

He was jailed for 11 years after being convicted of downloading articles from democracy sites abroad.

Amnesty said: "Everyone detained purely for peacefully publishing their views or other information on the internet or for accessing certain websites are prisoners of conscience.

"They should be released immediately and unconditionally."

Various attempts by Chinese officials to control the internet have been reported - such as the temporary banning of the Google search engine in September.

The Amnesty report said other action taken to control online information included:

Blocking foreign websites

Creation of internet police

Closure of sites with articles on corruption or critical of the government

Amnesty urged the Chinese Government to review its regulations restricting freedom of expression to comply with international standards.

International 'responsibility'

It also raised concerns that overseas producers were selling monitoring software to China which had been used for censorship.

"As China's role as an economic and trading partner grows, multinational companies have a particular responsibility to ensure that their technology is not used to violate fundamental human rights," the group said.

China is a country ruled by law - all people must abide by the laws and regulations

Government spokesman Kong Quan

But government spokesman Kong Quan rejected the tone of the report, which he had not seen.

"The Amnesty International organisation in the past has often issued statements with no basis whatsoever," he said.

"China is a country ruled by law - all people must abide by the laws and regulations."